Operating halfway between Earth and the Sun on March 2, 2022, the European Space Agency-led Solar Orbiter spacecraft recorded an hour-and-a-half-long crossing through a giant magnetic switchback measuring roughly 2.75 million kilometers across, allowing researchers to trace the solar wind anomaly directly back to its birthplace on the Sun.
Solar Orbiter Captures a Giant S-Shaped Bend in Space
The European Space Agency mission launched on 10 February 2020 carrying onboard magnetometers, particle sensors, and telescopes designed to image the solar disk from space.
The spacecraft made a serendipitous crossing through a massive magnetic bend in the solar wind while cruising through the solar system at roughly half the distance between Earth and the Sun.
Scientists had previously detected these S-shaped kinks, known as switchbacks, from a distance and used Solar Orbiter observations in 2022 to confirm their predicted geometry.
During the encounter, the spacecraft recorded elevated readings that persisted for roughly an hour and a half.
Given the spacecraft speed of around 30 to 40 kilometers per second, researchers calculated the radial size of the structure at about 2.75 million kilometers.
The switchback’s passing speed was approximately 450 to 460 kilometers per second.
That physical span reaches roughly six times the distance from the Earth to the Moon and about 3.5 times the radius of the Sun itself.
Heavy Ion Sensors Reveal a Million-Degree Solar Corona Origin
The instrument detected a distinct mixture of charged carbon and oxygen ions that had been stripped of their electrons during that hour-and-a-half crossing. Researchers examined data captured by the spacecraft’s Heavy Ion sensor to understand where the anomaly originated.
There was a noticeable decrease in helium levels compared to expected baseline measurements.
Solar Orbiter flew through a very large switchback.
Jesse Coburn of CNRS/LPP, France, lead author of a new paper in Nature Astronomy, via Universemagazine
Interchange Reconnection and Wave Dynamics Shape the Solar Wind
Heliophysicists debated two main hypotheses regarding switchback creation for years. They questioned whether the kinks formed through deep-space turbulence within the solar wind itself or originated inside the intensely hot solar corona.
The new particle data points directly to the latter through a mechanism known as interchange reconnection.
This allowed us to sample rarely observed particles there that carry distinctive fingerprints of their origins.
Jesse Coburn of CNRS/LPP, France, lead author of a new paper in Nature Astronomy, via Universemagazine
Interchange reconnection occurs when open magnetic field lines, which stretch far into space like highway routes, interact with closed magnetic loops anchored at both ends to the solar surface.
When these opposing fields collide, they break and reconnect in a modified configuration, slingshotting superheated plasma outward into space.
There are two main competing theories about how switchbacks—and, along with them, the solar wind—form.
Jesse Coburn of CNRS/LPP, France, lead author of a new paper in Nature Astronomy, via Universemagazine
The particular mixture of particles detected by Solar Orbiter provides compelling evidence for a formation process known as interchange reconnection.
Jesse Coburn of CNRS/LPP, France, lead author of a new paper in Nature Astronomy, via Universemagazine
Reconnection launches the structure near the solar surface.
Subsequent wave dynamics and turbulence take over to shape its movement as it travels through the solar system.
Protecting Space Infrastructure from Extreme Solar Storms
Unraveling the physics behind magnetic switchbacks carries practical implications for monitoring space weather and safeguarding technology across Earth and near-Earth orbit.
The solar wind connects Earth to the Sun, and understanding its dynamics is crucial to how we can protect our planet from extreme space conditions.
Daniel Müller, ESA’s Solar Orbiter project scientist, via Universemagazine
The same magnetic forces that generate switchbacks also drive violent solar storms capable of disrupting satellites, power grids, and communication networks.
The more we know, the better we can prepare for solar storms to protect our space infrastructure and technology.
Daniel Müller, ESA’s Solar Orbiter project scientist, via Universemagazine
Researchers caution that this detailed investigation examines one particularly large switchback and does not establish that every single magnetic kink shares an identical history.
Establishing whether all switchbacks form through this specific mechanism requires gathering additional crossing measurements through the mission’s ongoing orbital passes.